--- old/src/share/vm/opto/compile.cpp Fri Dec 12 19:19:37 2008 +++ new/src/share/vm/opto/compile.cpp Fri Dec 12 19:19:37 2008 @@ -2192,6 +2192,7 @@ case Op_DecodeN: assert(!n->in(1)->is_EncodeP(), "should be optimized out"); + assert(n->in(0) == NULL, "no control"); break; case Op_EncodeP: { --- old/src/share/vm/opto/macro.cpp Fri Dec 12 19:19:38 2008 +++ new/src/share/vm/opto/macro.cpp Fri Dec 12 19:19:38 2008 @@ -1724,6 +1724,13 @@ if (klass_node == NULL) { Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes()); klass_node = transform_later( LoadKlassNode::make(_igvn, mem, k_adr, _igvn.type(k_adr)->is_ptr()) ); +#ifdef _LP64 + if (UseCompressedOops && klass_node->is_DecodeN()) { + assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity"); + klass_node->in(1)->init_req(0, ctrl); + } else +#endif + klass_node->init_req(0, ctrl); } Node *proto_node = make_load(ctrl, mem, klass_node, Klass::prototype_header_offset_in_bytes() + sizeof(oopDesc), TypeX_X, TypeX_X->basic_type());